Chiller performance lacking, Defective?

[keigle]

Hello I just hooked up my 1/3 hp delta star chiller and it does not seem to be working as well as I had expected.

My tank is about 230g of water volume with about 800gph going through the chiller.

Today it was 90 in my house and with my lights off all day my chiller was not able to keep the temperature down to 81, even with fans and ice.

I know that the chiller is working because the tank water temp is 82.9 (would still be climbing without the ice) while the chiller outflow temp is 81.9. Is that about right performance wise for these chillers or is something up with my unit?

Dr. Fosters and Smiths specs on this chiller say it should be able to pull up to 250g 15degrees below ambient air temperature. Are they way off on this and I should have bought a 1/2 hp to be able to keep my lights on on hot days or should I have my chiller checked out?

Thanks
Jeff

BTW my tank is a 215 with 3 250hqi, 3 100w t-5, Iwaki 30, and 2 tunze 6100. I am using a aqauclear 901 @900gph to run water through the chiller at 0 head.

[PJSEA]

Make sure your inlet and outlet lines are connected correctly.
Your unit might be undersized for your heat load but you were not at the extreme of ambient conditions.
You might consider trying to bump up your flow thru the chiller.

[TwistedTiger]

<a href=showthread.php?s=&postid=7800253#post7800253 target=_blank>Originally posted</a> by keigle
Today it was 90 in my house

Normally tank water is going to be a little warmer than the house temp with all the pumps and such so if it was indeed 90 inside then your chiller was working overtime. Are you punishing yourself for some reason, why not turn on the AC?

[keigle]

Thanks guys. The input and output is hooked up corectly. Aqualogic rates the flow through this model as 600-1200 gph, so I don't know how much more performance I would get by buying a new pump.

Unfortunately I live in an older log cabin. The window hindges move towards the center when you open them so window ACs will not fit. I also rent so big holes in the wall are a no go.

[BONDQ]

<a href=showthread.php?s=&postid=7800570#post7800570 target=_blank>Originally posted</a> by TwistedTiger
Normally tank water is going to be a little warmer than the house temp with all the pumps and such so if it was indeed 90 inside then your chiller was working overtime. Are you punishing yourself for some reason, why not turn on the AC?

Keigle, I think you answered your own question here.

Keep in mind that chillers, are just advanced heat exchangers.

Your source of cooling (your room), must actually be cold; otherwise you're just moving around a bunch of water.

I would also recommend a 1/2 HP for your set-up especially since you have Metal Halides and you keep your house warm. It will be more efficient for you in the long run.

You may also want to try some evaporative cooling by blowing air across your sump. This can really help.

[smcdonn]

<a href=showthread.php?s=&postid=7800636#post7800636 target=_blank>Originally posted</a> by BONDQ
Keigle, I think you answered your own question here.

Keep in mind that chillers, are just advanced heat exchangers.

Your source of cooling (your room), must actually be cold; otherwise you're just moving around a bunch of water.



I am sorry to say but these statements are 100% wrong. Chillers are not advanced heat exchangers, they are actually compact A/C units. When it's 100 degrees outside your A/C in your house can still keep the house at 70 degrees right? Chillers work on the same principal. The efficiency will indeed go down the hotter it gets in the room but it will still be extracting heat. Cheers

[Fiziksgeek]

Sounds like the chiller is too small. With your heat load and water volume, the chiller will need to work pretty hard. Like most equipment, its better to get it a bit oversized.

Also, is the chiller outside? If not, your just dumping the heat back into the room with the tank, and the water is heating back up.

The worst hit to its efficiency is probably the ambient temp of the room. Usually, they need to be in air that is 90 or 95 degrees. The hotter it is, the more the chiller has to work to cool the water.

[RichConley]

<a href=showthread.php?s=&postid=7800776#post7800776 target=_blank>Originally posted</a> by smcdonn
I am sorry to say but these statements are 100% wrong. Chillers are not advanced heat exchangers, they are actually compact A/C units. When it's 100 degrees outside your A/C in your house can still keep the house at 70 degrees right? Chillers work on the same principal. The efficiency will indeed go down the hotter it gets in the room but it will still be extracting heat. Cheers

An AC can exhaust to the outside. In this case, it can't.

Its 90 degrees. The unit says it will pull down 15. That gives you 75. Add in all your equipment, adn 750w of light... and you're back over 80.

You need a bigger chiller.

[asmujica]

Can you place the chillers exhaust to go outside. Also I doubt that pump has zero head and is giving the chiller the suficient water it needs.

[smcdonn]

<a href=showthread.php?s=&postid=7802334#post7802334 target=_blank>Originally posted</a> by RichConley
An AC can exhaust to the outside. In this case, it can't.

Its 90 degrees. The unit says it will pull down 15. That gives you 75. Add in all your equipment, adn 750w of light... and you're back over 80.

You need a bigger chiller.

I realize that an AC can exhaust the heat outside and a chiller can't. But it is still removing heat from the water and dumping it in the room. Dumping this heat to the room will indeed heat it up causing the tank to warm by conduction. What you need to understand though is that even if you COULD put the chiller outside and dump the heat outside of the room, the air outside is already going to be VERY hot compared to the air indoors lowering the efficiency of the chiller and hence it wont perform as well and your back to square one. Overall I do agree you need a bigger chiller with over 200 gallons of water to cool though. Cheers

[BONDQ]

<a href=showthread.php?s=&postid=7800776#post7800776 target=_blank>Originally posted</a> by smcdonn
I am sorry to say but these statements are 100% wrong. Chillers are not advanced heat exchangers, they are actually compact A/C units. When it's 100 degrees outside your A/C in your house can still keep the house at 70 degrees right? Chillers work on the same principal. The efficiency will indeed go down the hotter it gets in the room but it will still be extracting heat. Cheers

Admittedly, I have over-simplified, but chillers are just freon phase-change devices. They do not actually ADD COLD to anything, they simply remove heat.

The freon EXPORTS hot from the water by blowing off the hot coils in the chiller into the air in the room. Then it changes phase and returns to remove additional heat.

How Stuff Works-AC (http://home.howstuffworks.com/ac.htm)

...AND YES, A Chiller IS A heat exchanger. The freon never touches the water, therefore it's cooling power is exchanged as the water passes by the Titanium coil. This means it is a heat exchanger.

If the room ambient termperture is high, you are GREATLY reducing the cooling efficiency of the chiller. Besides this, the ambient air temperature is forcing the water to be hotter.

The point I'm trying to make is that the chillers job is to transport heat from one point to the other. If the other point is HOT, then you're not going to cool the water very well. Well, not without running the chiller constantly anyway.

Regardless, I have 1/2HP on 300G and feel that's a good matchup. JBJ's website recommended it after I calculated all of my pumps and lighting. I thought it was over-sized, but if I had it to do over, I might have even picked a 3/4HP.

It's not that your 1/3HP won't do the job, it will just take it longer to do it, and will need to run more often.

[keigle]

So I talked to Aqualogic today, the long and short of it is that if it is working and not dropping the temperature enough than its too small. They said that there are too many variables that add heat to a reef tank which is why the temperature pull down of 15 degrees on 250g is with no lights, or pumps (makes me wonder how the run the chiller on those systems?).

They said that they recommend a generic cutting of those numbers in half on reef tanks - as in it will pull down 125g 15degrees below ambient temperature. Unfortunately, as he said, LFS don't always provide the best information. However, they also don't do anything to help like putting that on the website, which of coarse I checked before I purchased, or in there manuals.

On a side note my house with no AC actually stays cooler than out side temps. While the chiller was running in a 90degree house it was actually 96 outside so I would lose more efficiency by having it outside ( at least until about 7pm)

So I guess that I am in the market for a new chiller - YEA!

[smcdonn]

I don't know how you do it. 90 inside is HOT. Honestly if your house stays at around 90, I would look at a 3/4 hp chiller. Even a 1/2hp chiller is going to be working overtime on a reeftank when it's trying to dump heat into a room that is already 90 degrees. So even one of those small $80 window units at LOWES wouldn't fit in one of your windows ehh. I feel sorry for you. Your in my prayers :)

[BONDQ]

You could get one of those vertical stand room A/C units.

They exhaust with a small vent (like a small dryer vent) to the outside. That should fit.

Give it a try, because 90 degrees in a house is no fun.

[smcdonn]

Yea my LFS has one of those. They work pretty well although I think there kinda pricey though. It would be killer if you could get one of those little window units to work. They are usually like 6,000 Btu/hr which is pretty good for such a compact unit and cheap too. They mass produce those things like there going out of style. Cheers

[keigle]

I actually have one of those vertical ACs. It was given to me and seems horribly inefficient compared to my window mounted ACs. It is like 9000+ BTUs and barely keeps up with 4000BTU window unit.

For anyone going ***, I live in three small separate buildings, two log cabins and a office/apartment over a garage. One of the cabins is just 12x24 and is just a home theater. The Vertical AC works ok in there but is just too weak to do anything in the larger house. The house that holds the tank is essentially one large room with cubicle walls to make bedrooms etc.

[golfish]

I've used the same chiller (AL Delta Star) on my systems for the past 5 years. Both systems top off at 190 gals. I've used as much as 3x400 watt MH's along with 4x55 watt PC's. The chiller always cooled very well. If the chillers doesn't have good air flow around it then it wont work very well. No matter how hot it is outside I'd still try to get it out there.

You might try placing a large fan next to the chiller so you get good air flow around it. If this works then your next step is moving it outside.